import java.util.Scanner;

/**
 * @author: gao
 * @create-date: 2025/5/16 22:13
 */

public class Solution {
    public int uniquePaths(int m, int n) {
        int[][] dp = new int[m + 1][n + 1];
        dp[0][1] = 1;
        for (int i = 1; i <= m; i++) {
            for (int j = 1; j <= n; j++) {
                dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
            }
        }
        return dp[m][n];
    }

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNext()) {
            int m = in.nextInt();
            int n = in.nextInt();
            Solution solution = new Solution();
            System.out.println(solution.uniquePaths(m, n));
        }
    }
}